Leads on:

Remember a Day (SFOS, 1968)
See-Saw (" ")
Paintbox (b-side to Apples and Oranges, 1967)
It Would Be So Nice (single, 1968)
Stay (OBC, 1972)
Wearing the Inside Out (DB, 1994)
Maybe a couple more I'm forgetting....

And he sings backup on many Floyd songs, a lot of them I haven't heard in a while so I can't be sure it's him.